Kinetics of Holographic Recording and Spontaneous Erasure Processes in Light-Sensitive Liquid Crystal Elastomers

Materials

Marko Gregorc³  Hui Li²  Valentina Domenici⁴  Gabriela Ambrožič¹  Martin Čopič³ 

[1] National Institute of Chemistry, Hajdrihova 19, Ljubljana, SI 1000, Slovenia; E-Mail:;Nankai University, TEDA APS, 23 Hongda Street, Tianjin 300457, China; E-Mail:;J. Stefan Institute, Jamova 39, Ljubljana, SI 1000, Slovenia; E-Mails:;Dipartimento di Chimica e Chimica Industriale, Università degli studi di Pisa, via Risorgimento, 35, Pisa 56126, Italy; E-Mail:

关键词: liquid crystal elastomers;    light-sensitive materials;    holographic lithography;    optical microstructuring;    recording kinetics;   

DOI  :  10.3390/ma5050741

来源: mdpi

【 摘 要 】

The optical mechanism for imprinting one-dimensional grating structures into thin films of a light-sensitive monodomain liquid crystal elastomer is investigated by analyzing the time dependence of optical diffraction properties. The recording kinetics shows an irregular oscillatory behavior, which is most expressed at small grating spacings and at temperatures close to the nematic-isotropic phase transition. The oscillations are attributed to the opto-mechanical response of the film, i.e., to contraction of the film during the recording process. At temperatures far below the nematic-isotropic phase transition, the spontaneous erasure kinetics exhibits exponential relaxation with relaxation time following the Arrhenius activation law. However, at temperatures close to the nematic-isotropic phase transition, the erasure process shows an interesting nonmonotonic behavior that we attribute to the non-linear relation between the concentration of the photo-transformed chemical groups and the nematic order parameter.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.